Sonographic imaging of normal and osteoarthritic cartilage

Assessment of validity, reliability, and feasibility of OMERACT ultrasound knee osteoarthritis scores in Egyptian patients with primary knee osteoarthritis

BACKGROUND

Ultrasound (US) can evaluate all joint components affected by knee osteoarthritis (KOA); however, standardized scoring of US-detected pathology is needed to improve its diagnostic and monitoring capabilities.

OBJECTIVES

To examine the validity, reliability, and feasibility of the Outcome Measures in Rheumatology (OMERACT) ultrasound scoring for KOA, comparing with clinical and radiography measures, using predefined cutoff values.

METHODS

This cross-sectional study included 75 Egyptian patients with primary KOA. All patients had Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, bilateral knee radiography, and ultrasonography. Inter-observer reliability of ultrasound was evaluated in 30 knees by another newly trained operator.

RESULTS

Most of the OMERACT-US KOA scores showed significant associations with WOMAC clinical scores, except for femoral cartilage damage and effusion. The synovitis score was significantly associated with WOMAC-pain score (p-value 0.046), while medial meniscus extrusion (MME) and medial osteophytes were significantly associated with WOMAC-stiffness score (p-value 0.009 and 0.023, respectively). MME and synovitis were significantly associated with WOMAC-physical score (p-value 0.035 and 0.020, respectively). The ultrasound scores also showed a strong correlation with radiographic scoring. Inter-observer reliability ranged from moderate to excellent agreement (k = 0.58 to k = 0.83); it was highest for lateral osteophytes (k = 0.83), good agreement for synovitis (k = 0.72), any osteophytes (k = 0.71), damage of femoral cartilage (k = 0.70), and moderate agreement for medial osteophytes (k = 0.58) and MME (k = 0.59).

CONCLUSION

OMERACT-US scoring system for KOA demonstrated validity, reliability, and feasibility for evaluating both structural and inflammatory components. Using cutoff values improved the scoring reliability for osteophytes and MME. Key Points • OMERACT-US scores provide a valid assessment of inflammatory and structural components of knee osteoarthritis. • The following changes may improve the performance of the OMERACT-US scores. a. The binary score for effusion and synovial hypertrophy can be omitted, as they have no added value. b. A semi-quantitative grading for effusion may capture the impact of effusion on clinical outcomes. c. Added cutoff values to score medial meniscal extrusion, osteophytes, and pathological effusion improved the respective scores' reliability. d. Applying the updated OMERACT definition of synovitis. • OMERACT-US scores are reliable to be used with a newly trained operator, particularly when cutoff values are included, and proper training time is provided. • The OMERACT-US score is feasible to be used in clinical practice, as the time taken to perform was short, even for a newly trained operator.

Diagnostic value of ultrasonography in knee osteoarthritis: A systematic review

Background

Knee osteoarthritis (KOA) is the most expected diagnosis for an arthropathy that causes discomfort and disability in older adults. Radiography is frequently used to assess patients with KOA and there have been few prior research evaluating the diagnostic efficacy of ultrasonography (US). The current study sought to assess the diagnostic efficacy of the US in identifying various characteristics of KOA in the scientific literature.

Materials and Methods

This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta Analyses statement. A systematic search in PubMed, Web of Science, Scopus, and Embase databases was completed in March 2023. This study focused on the diagnostic value of US in KOA, including sensitivity, specificity, positive predictive value, and negative predictive value. The quality assessment was conducted using the Joanna Briggs Institute critical appraisal tools.

Results

Out of 552 records of database searches, finally, two studies met this systematic review's eligibility criteria and were included in the study. Both of the included studies were cross sectional studies. US demonstrated remarkable sensitivity with adequate specificity for the detection of radiographic knee OA; however, it was found not to be an appropriate method for the detection of early KOA.

Conclusion

This study as the first systematic review aims to evaluate the diagnostic performance of US in detecting KOA. These findings shed light on the importance of investigating the different US features in the evaluation of KOA to reach appropriate sensitivity and specificity in the diagnosis.

Mandibular condyle volumes are associated with facial asymmetry in patients with cleft lip and palate: A retrospective cohort study

This study compares condylar volumetric asymmetry and facial asymmetry in patients with cleft lip and/or palate (CLP) and controls. The mandibular condyle is important to facial growth, but its role in facial asymmetry for those with CLP has not been described. Condylar volumes and mandibular asymmetry were retrospectively calculated using Mimics Version 23.0 (Materialise, Leuven, Belgium) from patients with CLP undergoing computed tomography (CT) imaging and a cohort of controls. A total of 101 participants, 60 with CLP and 41 controls, had mean condylar volumetric asymmetry of 16.4 ± 17.4 % (CLP) and 6.0 ± 4.0 % (controls) (p = 0.0002). Patients with CLP who had clinically significant chin deviation (>4 mm) had more asymmetric condyles than those without significant chin deviation (p = 0.003). The chin deviated toward the smaller condyle in patients with facial asymmetry more often than in patients without facial asymmetry (81 % vs. 62 %, p = 0.033). While controls had some degree of condylar asymmetry, it tended to be milder and not associated with facial asymmetry. There is a greater degree of condylar volumetric asymmetry in patients with CLP compared to individuals in the general population. Clinically significant facial asymmetry in CLP is associated with a higher degree of condylar asymmetry, with the facial midline deviating toward the smaller condyle.

Utilizing MSK Ultrasound for Comprehensive Assessment of the Femoral Trochlea: A Game Changer in Sports Medicine

Musculoskeletal (MSK) ultrasound has emerged as a valuable tool for sports physical therapists in the assessment and treatment of various knee pathologies. Its ability to provide high-resolution images of soft tissue and superficial bone surfaces makes it especially useful for sports physical therapists and orthopedic clinicians. Specifically, MSK-ultrasound is increasingly recognized as a potent tool for the assessment of the femoral trochlea. Its non-invasive nature and dynamic imaging capabilities make it particularly suited for visualizing the femoral trochlea, a critical component in knee function and biomechanics. The use of MSK ultrasound in the evaluating the femoral trochlea provides sports medicine professionals with a dynamic, non-invasive, and cost-effective means to diagnose, and monitor knee-related injuries. This article delves into the utility of MSK ultrasound in the anatomical and functional assessment of the femoral trochlea, elucidating its benefits, limitations, and clinical implications for athletes.

Effects of gait training with auditory biofeedback on biomechanics and talar cartilage characteristics in individuals with chronic ankle instability: A randomized controlled trial

BACKGROUND

Altered walking gait is a typical impairment following ankle sprains which may increase susceptibility to recurring injuries and development of posttraumatic osteoarthritis at the ankle. There is a lack of targeted gait training interventions focusing on specific modifications in individuals with chronic ankle instability (CAI). Additionally, there is a need to focus on cartilage health changes following gait training to mitigate osteoarthritis progression.

RESEARCH QUESTION

To determine the immediate and retention effects of gait training using auditory biofeedback (AudFB) in patients with chronic ankle instability (CAI) on biomechanics and talar cartilage characteristics.

METHODS

Eighteen participants with CAI were randomly assigned into Control (n = 7) or AudFB (n = 11) groups. Each group completed 8-sessions of 30-minute treadmill walking. The AudFB group received biofeedback through a pressure sensor fashioned to the lateral foot and instructions to walk while avoiding noise from the sensor. The Control group did not receive instructions during sessions. An in-shoe insole system measured peak pressure, maximum force, and center of the pressure gait line (COP) during walking. Ultrasonography captured talar cartilage thickness and echo intensity before and after walking. Biomechanics and ultrasound were measured at baseline, immediately, and 1-week after the intervention. Repeated measures mixed-methods analysis of variance assessed changes within groups across time.

RESULTS

The AudFB group significantly reduced pressure and force in the lateral foot and medially shifted their COP at Immediate and 1-week Post. There were no observed changes in the Control group. In addition, neither group demonstrated changes in ultrasound measures at follow-up.

SIGNIFICANCE

Implementation of auditory biofeedback during gait training can be a valuable tool for clinicians treating patients with CAI.

Plantar pressure profile during walking is associated with talar cartilage characteristics in individuals with chronic ankle instability

BACKGROUND

Individuals with chronic ankle instability typically present with abnormal gait patterns favoring the lateral foot. This gait pattern may alter cartilage stress potentially increasing the risk of osteoarthritis development, thus exploring this relationship may provide insights for early interventions. The purpose of this study was to examine the relationship gait biomechanics and talar articular cartilage characteristics.

METHODS

Talar articular cartilage was assessed with ultrasound at rest and after walking for 30-min in twenty-five adults (14 females, 22.6 ± 3.12 years, 168.12 ± 9.83 cm, 76.00 ± 15.47 kg) with chronic ankle instability. Cartilage was segmented into Total, Medial, and Lateral regions. During the 30-min walking period, plantar pressure of the entire foot was recorded every 5-min and condensed to create a biomechanical loading pattern and center of pressure gait line. Relationships between resting cartilage thickness and echo intensity, changes in thickness and echo intensity, and plantar pressure profiles were assessed with correlation coefficients.

FINDINGS

There was a significant relationship between plantar pressure in the lateral forefoot and medial talar cartilage deformation (r = 0.408, p < .05). Early stance center of pressure was correlated with deformation in the total (r = 0.439-0.524) and lateral (r = 0.443-0.550) regions (p < .05). There were no significant correlations between echo intensity and biomechanics.

INTERPRETATION

This study contributes to the growing evidence that talar cartilage strain patterns are associated with biomechanics during walking. Further validation is needed to determine a causal relationship between biomechanics and ultrasound cartilage characteristics after ankle sprains. In addition, research should continue determining the utility of ultrasound to monitor joint health after musculoskeletal injuries.

Ultrasound Imaging Acquisition Procedures for Evaluating the First Metatarsophalangeal Joint: A Scoping Review

The aim of this scoping review was to investigate ultrasound imaging (USI) acquisition procedures and guidelines used to assess the first metatarsophalangeal joint (MTPJ). MEDLINE, CINAHL, AMED and SPORTDiscus were systematically searched in May 2021. Studies were included if they used grey-scale USI or power Doppler and reported a USI procedure to assess the first MTPJ. Screening and data extraction were performed by two independent assessors. The scoping review was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for scoping reviews (PRISMA-ScR). A total of 403 citations were identified for screening, with 36 articles included in the final analysis. There was wide variation in USI acquisition procedures used to evaluate the first MTPJ. Inconsistencies in reporting may be attributable to the number of elements the USI acquisition procedure encompasses, which include the model of the USI device, the type of transducer, USI modalities and settings, patient position, transducer orientation, surfaces scanned and the scanning technique used. The review found inconsistencies against international guidelines and limited implementation of consensus-based recommendations to guide image acquisition. Current guidelines require further refinement of anatomical reference points to establish a standardised USI acquisition procedure, subsequently improving interpretability and reproducibility between USI studies that evaluate the first MTPJ.

High-Frequency Acoustic Imaging Using Adhesive-Free Polymer Transducer

The piezoelectric polymer PVDF and its copolymers have a long history as transducer materials for medical and biological applications. An efficient use of these polymers can potentially both lower the production cost and offer an environment-friendly alternative for medical transducers which today is dominated by piezoelectric ceramics containing lead. The main goal of the current work has been to compare the image quality of a low-cost in-house transducers made from the copolymer P(VDF-TrFE) to a commercial PVDF transducer. Several test objects were explored with the transducers used in a scanning acoustic microscope, including a human articular cartilage sample, a coin surface, and an etched metal film with fine line structures. To evaluate the image quality, C- and B-scan images were obtained from the recorded time series, and compared in terms of resolution, SNR, point-spread function, and depth imaging capability. The investigation is believed to provide useful information about both the strengths and limitations of low-cost polymer transducers.

Imaging of knee osteoarthritis: A review of current evidence and clinical guidelines

BACKGROUND

Knee osteoarthritis (OA) is one of the most common and debilitating degenerative joint diseases worldwide. While radiography is the most commonly used imaging modality, it is associated with drawbacks which newer modalities such as magnetic resonance imaging (MRI) and ultrasound could overcome. Nevertheless, the role of imaging in clinical practice and research in knee OA has not been clearly defined. Furthermore, guidelines on imaging in knee OA from different authoritative bodies have not been compared in previous studies. Therefore, the present review aims to summarise existing evidence and compare guidelines on the use of different imaging modalities in evaluating knee OA.

METHODS

This is a narrative review based on a search of published clinical guidelines and the PubMed database for articles published between 1 January 1990 and 31 May 2020.

RESULTS

There is no broad consensus on the value of imaging in patients with typical OA presentation. If imaging is required, current evidence and clinical guidelines support the use of radiography and MRI as first- and second-line diagnostic modalities respectively. Since radiographic OA features have limited sensitivity and do not manifest in early stages, MRI is the preferred option for whole-joint evaluation in OA research. Discrepancies exist regarding the use of alternative imaging modalities including ultrasound, computed tomography and nuclear medicine.

CONCLUSION

Radiography and MRI are the imaging modalities of choice. Other modalities have their respective advantages, and more research is warranted for the standardisation of image acquisition and interpretation methodology, in order to evaluate their validity, reliability and responsiveness in OA research.

Sonography: a sensitive and specific method for detecting trochlear cartilage pathologies

PURPOSE

MRI is now the modality of choice for evaluating articular cartilage. Nevertheless, it has some general drawbacks. Some patients cannot undergo MRI, and in others US scan could be the first examination and cartilage should be evaluated. Ultrasound could be a useful method for detecting trochlear cartilage low-grade lesions. In this study, our goal was to evaluate the efficacy of ultrasonography in detecting these lesions.

METHODS

All patients referred to our hospital, from July 2018 to July 2019, who were arthroscopic candidates due to sport-related pathologies, underwent ultrasound scan 1 day prior to surgery. Ultrasound assessment was performed by an expert radiologist, with a 13-MHz probe, located transversely proximal to the patella in different degrees of knee flexion to assess trochlear lesion grade and thickness. Arthroscopic examination of all patients was performed by an experienced orthopedic knee surgeon (second author). Sensitivity and specificity of ultrasound were calculated.

RESULTS

A total of 48 patients were involved in the study with a mean age of 33.2 years (SD: 9.7), between 19 and 51 years of age. Patients were 81% male (39 patients). The sensitivity of ultrasound in grading of trochlear cartilage lesion was 100%, meanwhile its specificity was 88.2% (30 cases had normal cartilage while this figure was 34 in arthroscopy).

CONCLUSION

Sonography is a low-cost, accessible diagnostic tool with high sensitivity and specificity for early detection of trochlear cartilage pathologies. It can play an important role as an outpatient diagnostic workup in patients with anterior knee pain.

Intra-articular infiltration of adipose-derived stromal vascular fraction cells slows the clinical progression of moderate-severe knee osteoarthritis: hypothesis on the regulatory role of intra-articular adipose tissue

Background

The infiltration of the stromal vascular fraction (SVF) of autologous adipose tissue to treat osteoarthritis has been used for several years demonstrating its safety and noticeable efficacy. This article presents clinical data from patients afftected by moderate and severe knee osteoarthritis demonstrating safety and clinical efficacy of the treatment when this autologous cell product is injected in the knee joint and patients evaluated post-operatively after 1 year. However, what do we know about the mechanism that underlies this clinical improvement? This article proposes, for the first time in our opinion, a hypothesis of the mode of action that involves structural and molecular interactions between SVF and infrapatellar fat pad (IFP). As consequence, there would be a re-education of intra-articular adipose tissue, which we consider a key player for the clinical effect observed in the mid and long term mainly due to immuno-regulatory mechanisms.

Methods

This is a retrospective and not controlled study that evaluated 50 patients (100 joints) ranging from 50 to 89 years old, separated by age cohorts. Clinical efficacy was assessed using the Lequesne, WOMAC, and VAS scales, by ultrasound control and quantification of the biochemical profiles of synovial fluid.

Results

There were no serious adverse effects. All the indexes studied showed a significant clinical improvement after 1-year follow-up for all ages and OA degree groups. This finding was correlated with the ultrasound observations and biochemical data, which show a marked decrease in catabolic and pro-inflammatory molecules (MMP-2, IL-1B, IL-6, and IL-8) and significant increase for anabolic and anti-inflammatory molecules (IGF-1 and IL-10).

Conclusions

We conclude that intra-articular SVF infiltration for knee OA treatment is safe and effective during 1 year. We propose that applied SVF cells cause a cascade of molecular and structural events that, through complex interactions between IFP and SVF, re-educating the intra-articular fatty tissue towards a homeostatic, protective, and anti-inflammatory function, which will ultimately promote the restructuring and regeneration of damaged tissues.

Standardized, musculoskeletal ultrasonographic reference values for healthy Korean adults

BACKGROUND/AIMS

To define standard reference values for musculoskeletal ultrasonography (MSUS) in Korea.

METHODS

A total of 251 healthy adults were recruited for this study. Ultrasonography was performed by experienced rheumatologists who had undergone four appropriate training programs in Korea. A General Electric LOGIQ electronic ultrasound device fitted with a 12 MHz linear transducer was employed. Mean values ± standard deviations (SDs) were defined as standard reference values. Intraclass correlation coefficients was employed to evaluate the extent of inter- and intraobserver agreement when MSUS measurements were made.

RESULTS

The 251 study participants included 122 males. Mean subject age was 28.6 years. The average bone-to-capsule distance of the right-side second and third metacarpophalangeal (MCP) joints were 0.68 and 0.72 mm respectively, and those of the left-side joints 0.62 and 0.68 mm. The cartilage thicknesses of the rightside second and third MCP joints were 0.55 and 0.55 mm, and those of the leftside joints were 0.55 and 0.56 mm, respectively. The bone-to-capsule distances of the right and left wrists were 0.80 and 0.82 mm. In 12.4% of participants (31/251), the erosion score of the humeral head was 1.71. In the right-side knee joint, mean cartilage thicknesses of the medial and lateral condyles were 1.86 and 2.03 mm in longitudinal scans. High overall interobserver agreement was evident after appropriate training that included instruction on standard MSUS methodology.

CONCLUSION

We defined standard reference values for MSUS in healthy Korean adults. The reliabilities of interobserver agreements were high after appropriate training program.

Finger Joint Cartilage Evaluated by Semiquantitative Ultrasound Score in Patients With Rheumatoid Arthritis

OBJECTIVE

Joint destruction in rheumatoid arthritis (RA) includes both bone and cartilage lesions. Since joint space narrowing (JSN) is not a direct evaluation of cartilage using radiography, we aimed to examine the validity of ultrasound (US) cartilage evaluation using a semiquantitative method in patients with RA.

METHODS

We enrolled 103 patients with RA who were in remission or showing low disease activity and 42 healthy subjects. The cartilage thickness of the bilateral metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of the second to fifth fingers was measured by US, and the recorded images were scored semiquantitatively using a scale of 0-2. In addition, the JSN of the corresponding joints was scored using a hand radiograph. The relationships between total cartilage thickness, its semiquantitative score, and JSN score were assessed using Spearman's rank correlation coefficients.

RESULTS

Total cartilage thickness was significantly thinner in patients with RA compared to healthy subjects for both the MCP and PIP joints (both P < 0.001). The semiquantitative sum of 16 joints ranged from 2 to 26 (median 8) in patients with RA, which was significantly greater than the 0-11 (median 4) in healthy subjects (P < 0.001). In patients with RA, the semiquantitative score showed a significant negative correlation with cartilage thickness (ρ = -0.64, P < 0.001) and a significant positive correlation with JSN score (ρ = 0.66, P < 0.001). Furthermore, these scores showed a significant correlation with RA disease duration.

CONCLUSION

A simplified and direct evaluation of finger joint cartilage damage by semiquantitative US score is valid and useful for patients with RA.

Knee-Cartilage Segmentation and Thickness Measurement from 2D Ultrasound

Ultrasound (US) could become a standard of care imaging modality for the quantitative assessment of femoral cartilage thickness for the early diagnosis of knee osteoarthritis. However, low contrast, high levels of speckle noise, and various imaging artefacts hinder the analysis of collected data. Accurate, robust, and fully automatic US image-enhancement and cartilage-segmentation methods are needed in order to improve the widespread deployment of this imaging modality for knee-osteoarthritis diagnosis and monitoring. In this work, we propose a method based on local-phase-based image processing for automatic knee-cartilage image enhancement, segmentation, and thickness measurement. A local-phase feature-guided dynamic-programming approach is used for the fully automatic localization of knee-bone surfaces. The localized bone surfaces are used as seed points for automating the seed-guided segmentation of the cartilage. We evaluated the Random Walker (RW), watershed, and graph-cut-based segmentation methods from 200 scans obtained from ten healthy volunteers. Validation against manual expert segmentation achieved a mean dice similarity coefficient of 0.90, 0.86, and 0.84 for the RW, watershed, and graph-cut segmentation methods, respectively. Automatically segmented cartilage regions achieved 0.18 mm localization accuracy compared to manual expert thickness measurement.

Subclinical crystal arthropathy: a silent contributor to inflammation and functional disability in knees with osteoarthritis-an ultrasound study

PURPOSE

This study aimed at investigating the prevalence of crystal deposits with knee osteoarthritis (OA) by ultrasonography and measure the inflammatory burden associated with crystal deposits in OA using WOMAC score.

METHODS

Adult patients with primary knee OA diagnosed according to the American College of Rheumatology criteria were included. Participants were subjected to history taking, clinical examination, knee US, and plain radiography. The EULAR and the OMERACT ultrasonography definitions and scanning protocols were used.

RESULTS

Fifty-three patients (44 females, 9 males) were enrolled. Mean values were 53.5 years ± 8.3 SD for age and 42.5 months ± 49.5 SD for disease duration. Crystals were detected by US in 73/106 knees (68.9%). Plain radiography revealed chondrocalcinosis in three patients. Mean values for WOMAC pain, stiffness, and disability scores were 14.38 ± 3.99, 4.93 ± 2.06, and 49.61 ± 13.06, respectively, with insignificant differences relative to presence of crystals (P > 0.05). Regression analysis revealed a 4.1-fold increase in the incidence of sonographic crystals with bursitis (OR = 4.13, CI = 1.5-11.2, p = 0.01) and a 3.2-fold increase in the incidence of sonographic crystals with synovial effusion (OR = 3.16, CI = 1.34-7.44, p = 0.01).

CONCLUSION

Subclinical crystals were detected in a considerable number of patients with primary knee OA. The incidence of crystal deposits was significantly higher in patients with bursitis and knee effusion.

Ultrasound imaging and guidance in the management of knee osteoarthritis in regenerative medicine field

Ultrasound (US) is an excellent imaging tool to evaluate most of the structures in the knee joint. US is useful in various applications of regenerative medicine, starting from the biomaterial harvesting stage of the procedures, it can thus/conveniently be used for the diagnosis and treatment of various forms of knee osteoarthritis (OA) where the interventions need to be carried out under US guidance. In this paper, we have reviewed US guided bioharvesting of venous blood, bone marrow and adipose tissue, the US evaluation of the knee joint and the relevant findings in knee OA along with US guided regenerative interventions for the knee joint.

A novel ultrasound scanning approach for evaluating femoral cartilage defects of the knee: comparison with routine magnetic resonance imaging

Background

This study aimed to assess a novel ultrasound (US) scanning approach in evaluating knee femoral cartilaginous defects, compared with magnetic resonance imaging (MRI, commonly used for knee imaging) and arthroscopy (gold standard).

Methods

Sixty-four consecutive patients (65 knees) were prospectively evaluated between April 2010 and July 2011.

Results

The overall sensitivity (62.2 and 69.4%), specificity (92.9 and 90.5%), accuracy (75.4 and 78.5%), and adjusted positive (88.7 and 90.4%) and negative predictive (69.5 and 73.3%) were similar for both radiologists (weighted κ = 0.76). Furthermore, agreement between grading by US and MRI was substantial (weighted κ = 0.61).

Conclusions

In conclusion, the novel US scanning approach allows similar diagnostic performance compared to routine MRI for knee cartilage defects. US is more accessible, easier to perform, and less expensive than MRI, with potential advantages of easier initial screening and assessment of cartilage defects.

Electronic supplementary material

The online version of this article (10.1186/s13018-018-0887-x) contains supplementary material, which is available to authorized users.

Regional Rheumatic Disorders and Rehabilitation in Older Adults: An Update

Musculoskeletal problems are the most frequently reported complaints among older adults living in the community. The impact of the aging process on skeletal muscles and joints can have a profound effect on the ability of individuals to function. This article reviews the rehabilitation medicine approach to the evaluation of older adults with regional rheumatic disorders and the rehabilitation medicine considerations for clinical intervention. Future research is required to gain a greater understanding of the subject matter and its impact on the provision of care and patients' quality of life.

Ultrasound for Early Detection of Joint Disease in Patients with Hemophilic Arthropathy

Joint bleeding represents the most commonly reported type of hemorrhage in patients affected by hemophilia. Although the widespread use of prophylaxis has been able to significantly reduce the onset of arthropathy, it has been shown that a non-negligible percentage of patients develop degenerative changes in their joints despite this type of treatment. Thus, periodic monitoring of the joint status in hemophilia patients has been recommended to identify early arthropathic changes and prevent the development or progression of hemophilic arthropathy. Ultrasound (US) has proven able to detect and quantify the most relevant biomarkers of disease activity (i.e., joint effusion and synovial hypertrophy) and degenerative damages (i.e., osteo-chondral changes) by means of scoring scales of increasing disease severity. In the present review, we have detailed major literature evidence about the use of US to assess joint status in hemophilia patients, focusing on signs of disease activity and degenerative damages. In particular, we have discussed recent evidence about "point-of-care" use patients with hemophilia.

Role of Ultrasonography in Knee Osteoarthritis

Ultrasound has become popular among rheumatologists as the first-choice imaging investigation for the evaluation and monitoring of osteoarthritis (OA). Because of recent improvement in technology, ultrasound has the ability to demonstrate and assess the minimal structural abnormalities, which involve the pathophysiology and progression of OA, such as articular cartilage, synovial tissue, bony cortex, and other soft tissue. Nowadays, ultrasonography is a promising technique for assessing soft tissue abnormalities such as joint effusion, synovial hypertrophy, Baker cyst, and other structural changes including the decrease in cartilage thickness, meniscus bulging, and formation of osteophyte. Ultrasonography not only possesses diagnostic potential in knee OA but also reveals long-term predictability for disease progress as imaging biomarker. Ultrasonography has also been proven as a useful tool in guiding therapeutic interventions and monitoring treatment effectiveness. This review addresses the utility, reliability, and potential utilization of ultrasonography as an imaging technique in knee OA.

Regular chondrocyte spacing is a potential cause for coherent ultrasound backscatter in human articular cartilage

The potential of quantitative ultrasound (QUS) to assess the regular cellular spacing in the superficial cartilage zones was investigated experimentally and numerically. Nine osteochondral samples, extracted from two human cadaver knee joints, were measured using a 50-MHz ultrasound scanning device and evaluated using Mankin score. Simulated backscattered power spectra from models with an idealized cell alignment exhibited a pronounced frequency peak. From the peak, cell spacing in the range between 15 and 40 μm between cell layers was detected with an average error of 0.2 μm. The mean QUS-based cell spacing was 28.3 ± 5.3 μm. Strong correlation (R²= 0.59, p ≤ 0.001) between spacing estimates from light microscopy (LM) and QUS was found for samples with Mankin score ≤3. For higher scores, QUS-based spacing was significantly higher (p ≤ 0.05) compared to LM-based spacing. QUS-based spacing estimates together with other QUS parameters may serve as future biomarkers for detecting early signs of osteoarthrosis.

Regional Rheumatic Disorders and Rehabilitation in Older Adults

Musculoskeletal problems are the most frequently reported complaints among older adults living in the community. The impact of the aging process on skeletal muscles and joints can have a profound effect on the ability of individuals with and without disabilities to function. This article reviews the rehabilitation medicine approach to the evaluation of older adults with regional rheumatic disorders, and the rehabilitation medicine considerations for clinical interventions. Future research considerations are encouraged in order to gain a greater understanding of the subject matter and its impact on the provision of care and patients' quality of life.

Association between the severity of femoral condylar cartilage erosion related to knee osteoarthritis by ultrasonographic evaluation and the clinical symptoms and functions

OBJECTIVE

To determine the association between the severity of femoral condylar cartilage erosion resulting from knee osteoarthritis (OA) by an ultrasonographic grading system and the clinical symptoms and functions.

DESIGN

Cross-sectional study.

SETTING

A tertiary center.

PARTICIPANTS

Participants (N=101) with and without subjective complaints of knee discomfort were consecutively enrolled. Patients who had ever received knee arthroplasty, who had inflammatory arthritis, and whose knee flexion range of motion was <90° were excluded. A total of 194 knees were evaluated.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

A semiquantitative ultrasonographic grading system was used to evaluate the severity of femoral condylar cartilage erosion. The clinical symptoms and functions were evaluated with the visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Lequesne index. The association of the VAS/WOMAC/Lequesne index with the ultrasonographic grading was assessed.

RESULTS

Positive linear associations were found between the ultrasonographic grading and the following: the VAS and the total scores and pain subscales of both the Lequesne index and WOMAC. Multivariate logistic regression analysis revealed grade-dependent association between VAS and ultrasonographic grading after adjusting for age, sex, and body mass index. The WOMAC and Lequesne index scores were associated with the ultrasonographic grading in more severe degrees, particularly in the pain subscales.

CONCLUSIONS

This semiquantitative ultrasonographic grading system may well reflect the clinical symptoms and functions related to knee OA as evaluated by the VAS, WOMAC, and Lequesne index. This method provides a more comprehensive description and measurement of knee OA.

A superficial hyperechoic band in human articular cartilage on ultrasonography with histological correlation: preliminary observations

Purpose:

To demonstrate the superficial hyperechoic band (SHEB) in articular cartilage by using ultrasonography (US) and to assess its correlation with histological images.

Methods:

In total, 47 regions of interest (ROIs) were analyzed from six tibial osteochondral specimens (OCSs) that were obtained after total knee arthroplasty. Ultrasonograms were obtained for each OCS. Then, matching histological sections from all specimens were obtained for comparison with the ultrasonograms. Two types of histological staining were used: Safranin-O stain (SO) to identify glycosaminoglycans (GAG) and Masson’s trichrome stain (MT) to identify collagen. In step 1, two observers evaluated whether there was an SHEB in each ROI. In step 2, the two observers evaluated which histological staining method correlated better with the SHEB by using the ImageJ software.

Results:

In step 1 of the analysis, 20 out of 47 ROIs showed an SHEB (42.6%, kappa=0.579). Step 2 showed that the SHEB correlated significantly better with the topographical variation in stainability in SO staining, indicating the GAG distribution, than with MT staining, indicating the collagen distribution (P<0.05, kappa=0.722).

Conclusion:

The SHEB that is frequently seen in human articular cartilage on high-resolution US correlated better with variations in SO staining than with variations in MT staining. Thus, we suggest that a SHEB is predominantly related to changes in GAG. Identifying an SHEB by US is a promising method for assessing the thickness of articular cartilage or for monitoring early osteoarthritis.

Sonographic assessment of healthy peripheral joints: evaluation according to demographic parameters

OBJECTIVES

To describe quantitative and semiquantitative sonographic joint measurements in healthy adults and compare them with demographic parameters.

METHODS

A cross-sectional study was conducted. Bilateral sonographic measurements of small, medium, and large joints were performed in 130 healthy volunteers, stratified into 5 age groups (A, 18-29; B, 30-39; C, 40-49; D, 50-59; and E, 60-80 years). Quantitative synovial hypertrophy measurements and semiquantitative synovial hypertrophy, power Doppler, bone erosion (score 0-3), and articular cartilage (score 0-4) measurements were performed by a blinded radiologist using a 6-18-MHz linear array transducer. The sonographic measurements were correlated with demographic parameters. The significant P value was set at .05.

RESULTS

A total of 6500 joint recesses were studied; the mean age ± SD of the participants was 44.8 ± 14.6 years, and 76.9% were women. The highest quantitative synovial hypertrophy values were found in the hip (6.4 mm) and talonavicular joint (2.6 mm). The joint recesses with a greater frequency of hypothetical pathologic semiquantitative scores were second metatarsophalangeal (78.8%) and first metatarsophalangeal (69.3%) for synovial hypertrophy, radiocarpal (17.7%) and first metatarsophalangeal (15.8%) for power Doppler, and posterior glenohumeral (23.1%) and ulnocarpal (4.2%) for bone erosion. The highest quantitative synovial hypertrophy values and the lowest semiquantitative synovial hypertrophy, power Doppler, bone erosion, and articular cartilage scores were observed in age group E (P < .046). There were positive correlations between the sonographic measurements and height, age, weight, and body mass index in 30.4%, 34.8%, 43.5%, and 47.8%, respectively, of all the joint recesses studied.

CONCLUSIONS

Sonographic changes in healthy peripheral joints were observed predominantly in the oldest group.

Feasibility of ultrasound imaging of osteochondral defects in the ankle: a clinical pilot study

Talar osteochondral defects (OCDs) are imaged using magnetic resonance imaging (MRI) or computed tomography (CT). For extensive follow-up, ultrasound might be a fast, non-invasive alternative that images both bone and cartilage. In this study the potential of ultrasound, as compared with CT, in the imaging and grading of OCDs is explored. On the basis of prior CT scans, nine ankles of patients without OCDs and nine ankles of patients with anterocentral OCDs were selected and classified using the Loomer CT classification. A blinded expert skeletal radiologist imaged all ankles with ultrasound and recorded the presence of OCDs. Similarly to CT, ultrasound revealed typical morphologic OCD features, for example, cortex irregularities and loose fragments. Cartilage disruptions, Loomer grades IV (displaced fragment) and V (cyst with fibrous roof), were visible as well. This study encourages further research on the use of ultrasound as a follow-up imaging modality for OCDs located anteriorly or centrally on the talar dome.

Articular cartilage degeneration classification by means of high-frequency ultrasound

CONTEXT

To date only single ultrasound parameters were regarded in statistical analyses to characterize osteoarthritic changes in articular cartilage and the potential benefit of using parameter combinations for characterization remains unclear.

OBJECTIVE

Therefore, the aim of this work was to utilize feature selection and classification of a Mankin subset score (i.e., cartilage surface and cell sub-scores) using ultrasound-based parameter pairs and investigate both classification accuracy and the sensitivity towards different degeneration stages.

DESIGN

40 punch biopsies of human cartilage were previously scanned ex vivo with a 40-MHz transducer. Ultrasound-based surface parameters, as well as backscatter and envelope statistics parameters were available. Logistic regression was performed with each unique US parameter pair as predictor and different degeneration stages as response variables. The best ultrasound-based parameter pair for each Mankin subset score value was assessed by highest classification accuracy and utilized in receiver operating characteristics (ROC) analysis.

RESULTS

The classifications discriminating between early degenerations yielded area under the ROC curve (AUC) values of 0.94-0.99 (mean ± SD: 0.97 ± 0.03). In contrast, classifications among higher Mankin subset scores resulted in lower AUC values: 0.75-0.91 (mean ± SD: 0.84 ± 0.08). Variable sensitivities of the different ultrasound features were observed with respect to different degeneration stages.

CONCLUSIONS

Our results strongly suggest that combinations of high-frequency ultrasound-based parameters exhibit potential to characterize different, particularly very early, degeneration stages of hyaline cartilage. Variable sensitivities towards different degeneration stages suggest that a concurrent estimation of multiple ultrasound-based parameters is diagnostically valuable. In-vivo application of the present findings is conceivable in both minimally invasive arthroscopic ultrasound and high-frequency transcutaneous ultrasound.

An ultrasound biomicroscopic and water jet ultrasound indentation method for detecting the degenerative changes of articular cartilage in a rabbit model of progressive osteoarthritis

It is important to assess the early degeneration of articular cartilage associated with osteoarthritis (OA) for early intervention and treatment planning. Previously, we have developed a high frequency ultrasound and water jet indentation method for the morphologic, acoustic and mechanical assessment of articular cartilage, using the enzymatic digestion as a model of osteoarthritic degeneration. No naturally degenerated articular cartilage has been tested with the developed method. In this study, we aimed to determine the usefulness of the developed method for detecting the natural degeneration of articular cartilage in a standard surgical model of OA in rabbits. Forty adult New Zealand white female rabbits were used in this study, which included 30 experimental rabbits undergoing the right anterior cruciate ligament transection surgery and 10 control rabbits. At the 3rd, 6th, and 9th week post-surgery, 10 experimental rabbits were sacrificed, respectively, for assessment of the knee cartilage quality. The cartilage at the medial and lateral femoral condyles and tibial plateaus (four points) was measured by the high frequency ultrasound biomicroscopy, the water jet ultrasound indentation and a contact mechanical indentation test before a histopathologic analysis for grading of degeneration severity. Measured parameters were compared among different groups classified either by post-surgery time or by histopathologic grade. The results showed a general trend of increase for ultrasound roughness index and a general trend of decrease for integrated reflection coefficient, stiffness coefficient from water-jet indentation and Young's modulus (E) from the mechanical indentation with the increase of post-surgery time. Comparisons among groups with different histopathologic grades showed similar trend with the increase of degeneration severity. The water jet ultrasound indentation method was demonstrated to be an effective method to measure the mechanical properties of the articular cartilage and with further development of arthroscopic ultrasound probe; it has the ability to assess the early degeneration of articular cartilage with measurement of morphologic, acoustic and mechanical properties of the cartilage in vivo.

Clinical, radiological and ultrasonographic findings related to knee pain in osteoarthritis

Background

Pain is the predominant symptom of knee osteoarthritis (OA) and the main reason of disability. Ultrasound is now one of the new imaging modality in Musculoskeletal medicine and its role in assessing the pain severity in the knee osteoarthritis is evaluated in this study.

Objectives

(1) To study the correlation between ultrasonographic (US) findings and pain score and (2) whether ultrasonographic findings show a better association of pain level than conventional X-rays in patients suffering from primary knee osteoarthritis.

Methods

In this multi-center study, 193 patients with primary knee OA were asked to score their average knee pain using the Western Ontario and McMaster Universities Arthritis (WOMAC) questionnaire;patients would then go for a radiological and an US evaluation of their painful knee. Findings from both imaging modalities will be studied with the associated pain score.

Results

Ultrasound showed that knee effusion has positive correlation with pain score upon walking (r = 0.217) and stair climbing (r = 0.194). Presence of suprapatellar synovitis had higher pain score on sitting (Spearman's Rank correlation  = 0.355). The medial(r = 0.170) and lateral meniscus protrusion (r = 0.201) were associated with pain score upon stair climbing.

Conclusions

Our study found that both imaging modalities shown some significant association with the aspect of pain; neither one is clearly better but rather complementary to each other. A trend is found in both modalities: walking pain is related to pathologies of the either the lateral or medial tibiofemoral joint(TFJ)while stair climbing pain is related to both tibiofemoral joint pathologies and also to the patellofemoral joint (PFJ) pathology. This suggested that biomechanical derangement is an important aspect in OA knee pain.

Imaging of rheumatoid arthritis

Increased awareness of the need for early diagnosis of rheumatoid arthritis and advances in the ability to effectively treat rheumatoid arthritis have made disease remission and maintenance of function a reality for many patients. However, identification of patients who are at risk for erosive disease remains a challenge. As more is learnt about risk factors for disease severity and the role of imaging techniques such as ultrasound and magnetic resonance imaging, the ability to prevent disease progression in the form of joint damage and its attendant deformity and functional limitation will further improve.

Application of real-time sonoelastography in musculoskeletal diseases related to physical medicine and rehabilitation

Real-time sonoelastography is a recently developed ultrasound-based technique that evaluates tissue elasticity in real time, and it is based on the principle that the compression of tissue produces a strain (displacement) that is lower in hard tissue and higher in soft tissue. Real-time sonoelastography provides information on tissue elasticity, in addition to the shape or vascularity, which is obtained via B-mode ultrasound. Similar to B-mode ultrasound, freehand manipulation with the transducer and real-time visualization are now available for real-time sonoelastography in actual clinical practice. Tissue elasticity not only varies among different tissues but also seems to reflect disease-induced alternations in tissue properties. Real-time sonoelastography was recently applied to the normal and pathologic tissues in muscle and tendon disorders, and it showed promising results and new potentialities. Therefore, it is expected to be a useful modality for providing novel diagnostic information in musculoskeletal diseases because tissue elasticity is closely related to its pathology. It can also be used as a research tool to provide insight into the biomechanics and pathophysiology of tissue abnormality.

Sensitivity and specificity of ultrasound in detecting (osteo)chondral defects: a cadaveric study

The long-term prognosis of cartilage lesions evolving into an eroding subchondral bone defect is not known. Longitudinal monitoring using ultrasound could assist in overall understanding. The aim of the work described in this article was to determine the feasibility of using ultrasound to detect small (osteo)chondral defects. On the anterior talar surface of 10 human cadaveric ankles, at most four defects were arthroscopically created: two pure chondral defects 3 and 1.5 mm in diameter and two osteochondral defects 3 and 1.5 mm in diameter. All ankles were examined by two observers, and their ultrasound observations were validated using computed tomography scans and photographs. Overall sensitivity was 96% for observer 1 and 92% for observer 2, and specificity for both observers was 100%. Sixty-eight percent and 79% of defect sizes were within relevant limits of agreement (-0.2 ± 1.0 mm), respectively. Ultrasound imaging has the potential to detect small (osteo)chondral defects located within visible areas.

Non-invasive imaging of cartilage in early osteoarthritis

Treatment for osteoarthritis (OA) has traditionally focused on joint replacement for end-stage disease. An increasing number of surgical and pharmaceutical strategies for disease prevention have now been proposed. However, these require the ability to identify OA at a stage when it is potentially reversible, and detect small changes in cartilage structure and function to enable treatment efficacy to be evaluated within an acceptable timeframe. This has not been possible using conventional imaging techniques but recent advances in musculoskeletal imaging have been significant. In this review we discuss the role of different imaging modalities in the diagnosis of the earliest changes of OA. The increasing number of MRI sequences that are able to non-invasively detect biochemical changes in cartilage that precede structural damage may offer a great advance in the diagnosis and treatment of this debilitating condition.

Tracking rheumatic disease through imaging

This review recounts the historical, current, and future involvement of radiology and imaging in the diagnosis, management, and follow-up of patients with various rheumatic conditions. Radiographs are the mainstay of imaging patients with rheumatic conditions, although magnetic resonance imaging and ultrasonography are routinely used for early diagnosis of disease. Computed tomography remains useful in evaluating the extent of involvement of inflammatory spondyloarthropathies that classically involve the axial skeleton and sacroiliac joints. Molecular imaging has begun to play an innovative role in evaluating patients with arthritis, aiming to identify disease earlier and provide greater specificity.

Ultrasonographic evaluation of knee joints in patients with Lyme disease

OBJECTIVE

The aim of this study was to evaluate the ultrasonographic images of patients with chronic knee pain and serologic features of Lyme disease.

METHODS

Seventy-six patients hospitalized in The Department of Infectious Diseases and Neuroinfections of the Medical University in Białystok, Poland were included in the study. Patients were divided into two groups: (1) the Lyme disease group included patients with pain in one or both knees and anti-Borrelia burgdorferi antibodies with symptoms lasting for over 6 months; (2) the control group included patients suffering from pain in one or both knees for over 6 months, but for whom B. burgdorferi infection was excluded.

RESULTS

The most frequent ultrasonographic finding in the Lyme disease group was effusion, and its frequency was significantly higher than in the control group. No patient in the control group presented with synovitis or cartilage damage, while these were quite frequent findings in the Lyme disease group. Baker's cysts were more frequent in the Lyme disease group, but this was statistically non-significant.

CONCLUSIONS

Ultrasonography may be useful in following the sequelae of Lyme disease. The abnormalities found in Lyme disease patients are non-specific and ultrasonography is not useful in the differential diagnosis.

Sonographic evaluation of femoral trochlear cartilage in patients with knee pain

OBJECTIVES

The purpose of this study was to investigate whether routine clinical sonographic evaluation of femoral trochlear cartilage can identify abnormalities in patients with knee pain.

METHODS

Short-axis sonograms of the femoral trochlear cartilage were obtained from 20 symptomatic knees in 20 consecutive patients (16 women and 4 men; mean age, 54 years; range, 35-75 years) and 20 knees in 10 asymptomatic control participants (7 women and 3 men; mean age, 52 years; range, 31-74 years). Articular cartilage thickness was measured at 3 locations in each knee, and thickness at each site was compared between patients and controls. Subsequently, images from patients and controls were randomly assorted and evaluated by 3 blinded musculoskeletal radiologists, who independently evaluated the femoral trochlear cartilage in each sonogram for cartilage clarity, grade, and presence or absence of cartilage calcifications, osteophytes, and subchondral bony irregularity. The radiologists were instructed to rate the most severe lesion in each evaluated region (medial trochlea, trochlear notch, and lateral trochlea). Cartilage clarity was defined as how well the cartilage borders could be distinguished from the overlying intra-articular soft tissues, and grade was defined as the severity of focal cartilaginous lesions.

RESULTS

Using the Student t test, there was no significant difference (P > .05) between cartilage thickness in patients and controls for any location measured. However, using repeated measures analysis of variance, there were significant differences (P = .02) for both decreased cartilage clarity (df = 1/28; F = 5.76) and increased grade (df = 1/28; F = 5.77) in patients. There was also a nonsignificant (P > .05) trend toward more frequent calcifications, osteophytes, and bony irregularity in patients.

CONCLUSIONS

Routine clinical sonography can identify femoral trochlear cartilage abnormalities in patients with knee pain and therefore can be a useful adjunct to other imaging tests for identifying arthritic changes in the knee.

Comparison of articular cartilage images assessed by high-frequency ultrasound microscope and scanning acoustic microscope

PURPOSE

The purpose of this study was to compare images of a newly developed high-frequency ultrasound imaging system (HFUIS) and scanning acoustic microscope (SAM) and to calculate their Pearson product moment correlations with a view to applying HFUIS for clinical use.

METHODS

Cylindrical cartilage-bone complexes from adult male Sprague-Dawley rats were obtained. The specimens were immersed in normal saline and scanned by HFUIS. Intensity by HFUIS was normalised by reflection from a steel plate at the same distance. After the scanning, specimens were fixed with paraformaldehyde, decalcified and embedded in paraffin. Thinly sliced tissues were prepared for SAM evaluation. After the scanning, three layers of articular cartilage (superficial, middle and deep) were independently evaluated and their relationships calculated.

RESULTS

The superficial and deep layers indicated high relative intensity, whereas the middle layer showed nonhomogeneous relative intensity by HFUIS. A high relative intensity by HFUIS and high sound speed area by SAM had strong correlations (Pearson product moment correlation, superficial layer 0.704, middle layer 0.731).

CONCLUSIONS

HFUIS produced high-resolution images of the articular cartilage and its intensity was strongly correlated with sound speed by SAM.

Reliability and validity of ultrasound imaging of features of knee osteoarthritis in the community

Background

Radiographs are the main outcome measure in epidemiological studies of osteoarthritis (OA). Ultrasound imaging has unique advantages in that it involves no ionising radiation, is easy to use and visualises soft tissue structures. Our objective was to measure the inter-rater reliability and validity of ultrasound imaging in the detection of features of knee OA.

Methods

Eighteen participants from a community cohort, had both knees scanned by two trained musculoskeletal sonographers, up to six weeks apart. Inter-rater reliability for osteophytes, effusion size and cartilage thickness was calculated by estimating Kappa (κ) and Intraclass correlation coefficients (ICC), as appropriate. A measure of construct validity was determined by estimating κ between the two imaging modalities in the detection of osteophytes.

Results

Reliability: κ for osteophyte presence was 0.77(right femur), 0.65(left femur) and 0.88 for both tibia. ICCs for effusion size were 0.70(right) and 0.85(left). Moderate to substantial agreement was found in cartilage thickness measurements. Validity: For osteophytes, κ was moderate to excellent at 0.52(right) and 0.75(left).

Conclusion

Substantial to excellent agreement was found between ultrasound observers for the presence of osteophytes and measurement of effusion size; it was moderate to substantial for femoral cartilage thickness. Moderate to substantial agreement was observed between ultrasound and radiographs for osteophyte presence.

Periosteal autograft for articular cartilage defects in dogs: MR imaging and ultrasonography of the repair process

BACKGROUND

Autologous periosteal grafting is used as treatment for cartilage defects.

PURPOSE

To assess the role of MR imaging and ultrasonography in the evaluation of the post-graft repair process with imaging and histologic correlation.

MATERIAL AND METHODS

Periosteal grafts obtained from the tibia of eight dogs were transplanted to the experimental cartilage defects in the femoral condyles (15 knees). The control group was comprised of three dogs (five knees). MR imaging using 4.7T and ultrasonography of the grafted specimens was performed at one, two, four, eight, and 16 weeks after transplantation. The animals were sacrificed at the time of imaging at the previously specified intervals. Histologic analysis with imaging correlation was subsequently performed.

RESULTS

All specimens taken from one to 16 weeks demonstrated periosteal proliferation in the graft. At one week, experimental cartilage defects were no longer present on MR imaging. Area of high signal intensity (SI) in the defect was present which corresponded to hemorrhage, edema, and fibrosis on histology. At two, four, and eight weeks, all but two graft demonstrated heterogeneous high SI on T2-weighted image, consistent with immature cartilage. At 16 weeks, all grafts showed heterogeneous isointense to adjacent cartilage on all sequences, which corresponded to dominant mature cartilage. The repair tissue near the exposed subchondral bone revealed heterogeneous high SI on T2-weighted images. This corresponded to the fibrosis with vascular penetration and edema. In the control group, no cartilage repair was noted within cartilage defects. The serial MR features of the grafted area correlated well with the histologic findings. Serial sonographic findings were not sufficient to provide the regenerated cartilage maturity.

CONCLUSION

MR imaging is capable of depicting the repair characteristics following periosteal grafting for articular cartilage defects. MR imaging may provide useful information in the assessment of the graft appearance with definite implications regarding the degree and success of incorporation.

Ultrasound in the diagnosis of clinical orthopedics: The orthopedic stethoscope

Ultrasonography has advantages over other imaging modalities in terms of availability and comfort, safety, and diagnostic potential. Operating costs are low compared with both computed tomography (CT) and magnetic resonance imaging (MRI). The portable equipment is accessible at locations distant from medical centers. Importantly, ultrasonography is performed while patients lie in a comfortable position, without pain or claustrophobia. Ultrasonography is a totally safe noninvasive imaging technique. In contrast to CT and X-rays, it does not emit ionizing radiation. Unlike MRI, it is safe for all patients, including those with cardiac pacemakers and metal implants, without any contraindications. Of the many indications for musculoskeletal ultrasonography, the evaluation of soft tissue pathology is particularly common. In addition, ultrasonography is useful for the detection of fluid collection, and for visualization of cartilage and bone surfaces. Color or power Doppler provides important physiological information, including that relating to the vascular system. The capability of ultrasonography in delineating structures according to their echotextures results in excellent pictorial representation. This imaging principle is based on physical changes in composition, as compared to imaging with MRI, which is based on changes in chemical composition. This article reviews the contribution of sonography to the evaluation of the musculoskeletal system.

Ultrasound biomicroscopy for the detection of early osteoarthritis in an animal model

RATIONALE AND OBJECTIVES

Osteoarthritis (OA) is a common disease, and early diagnosis is essential for preventing further cartilage destruction and decreasing severe complications. Ultrasound biomicroscopy (UBM) is sensitive for detecting minute lesions in tissue because of its higher resolution, but its B-mode characterization of the early stage of OA has not been widely studied. The aim of this study was to determine the usefulness of UBM for detecting the early stage of OA using a rabbit model of early OA.

MATERIALS AND METHODS

Eighteen adult New Zealand White female rabbits were used in this study, which included 12 rabbits that underwent transections of the left anterior cruciate ligament and six control rabbits. At 2, 4, and 6 weeks after surgery, four experimental rabbits and two control rabbits were euthanized. UBM was performed to evaluate the articular cartilage surfaces of the left knee, using a 55-MHz transducer. All the articular cartilage surfaces were independently assessed in blinded fashion by two radiologists for the severity of OA. The value of UBM, interobserver reliability, and the concordance between UBM and pathologic grades were determined.

RESULTS

For the first radiologist, the sensitivity, specificity, positive predictive value, and negative predictive value of UBM for the diagnosis of OA were 91%, 83%, 89%, and 86%, respectively. For the second radiologist, the sensitivity, specificity, positive predictive value, and negative predictive value of UBM were 93%, 86%, 91%, and 89%, respectively. The concordance between UBM and pathologic grades for both radiologists was high (κ = 0.72 and 0.76), and the interobserver agreement was high (κ = 0.80).

CONCLUSIONS

UBM can be used to evaluate cartilage defects in an animal model, and further study is needed to determine whether this technique can be valuable for detecting early OA in humans.